Unit 4
4 marks · EasyA triangle has base cm and height cm. Its area is used to create a bar chart showing the frequencies of different shapes made by students.
Calculate the area of the triangle.
In the bar chart, the frequency for triangles is 9, rectangles 5, and circles 6. What is the mean number of shapes per type?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) 30 cm^2
(b) 6.67
Common mistakes: Using wrong area formula; Not dividing by number of types for mean
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Identifies and uses area formula for triangle
A1 (a) · 1 mark · Area calculated as 30 cm^2
M2 (b) · 1 mark · Adds frequencies and divides by 3 for mean
A2 (b) · 1 mark · Mean calculated correctly as 6.67
Worked solution
a) cm².
b) Total frequency: 9 + 5 + 6 = 20. Number of types = 3. Mean = 20 / 3 = 6.67.